CAPT Joseph John Rochefort, USN
May 12, 1900 – July 20, 1976
Captain Joseph John Rochefort was a major figure in the U.S. Navy’s cryptologic and intelligence developments from 1925 to 1947. He headed the Navy’s fledgling cryptanalytic organization in the 1920s and provided singularly superb cryptologic support to the U.S. fleet during World War II, leading to victory in the war in the Pacific. At the end of his career (1942-1946), Rochefort successfully headed the Pacific Strategic Intelligence Group in Washington.
Rochefort was born in 1898 and enlisted in the navy in 1918. He was commissioned an ensign after graduation from the Stevens Institute of Technology. Rochefort’s tours ashore included cryptanalytic training under both Captain Laurance Safford and Agnes Meyer Driscoll in 1925; a stint as second chief of the Department of Naval Communications’ newly created cryptanalytic organization, OP-20-G, from 1926 to 1929; training in the Japanese language from 1929 to 1932; and a two-year intelligence assignment in the Eleventh Naval District, San Diego, from 1936 to 1938. Until 1941, Rochefort spent nine years in cryptologic or intelligence-related assignments and fourteen years at sea with the U.S. fleet in positions of increasing responsibility.
In early 1941, Laurance Safford, again chief of OP-20-G in Washington, sent Rochefort to Hawaii to become Officer in Charge (OIC) of Station Hypo in Pearl Harbor. The reasons for Rochefort’s appointment were obvious: he was an expert Japanese linguist, an experienced and very talented intelligence analyst, and a trained cryptanalyst.
Rochefort hand-picked many of Hypo’s augmentees, and it contained the Navy’s best cryptanalysts, traffic analysts, and linguists, including Thomas Dyer, Wesley A. (Ham) Wright, Joseph Finnegan, General Alva Lasswell, Thomas Huckins, and Jack Williams.
After the Japanese attack on Pearl Harbor, Rochefort and the Station Hypo experts were eventually able to read enough of Japanese naval communications to provide daily intelligence reports and assessments regarding Japanese force disposition and intentions. During the peak month of May 1942, Rochefort reviewed, analyzed, and reported on as many as 140 decrypted messages per day. These reports went directly to the highest-ranking fleet commanders.
The most significant cryptologic success was the timely and accurate support provided by Rochefort and his unit surrounding the Battle of Midway, considered by many to be the turning point of the war in the Pacific. Station Hypo provided accurate and timely intelligence reports for the rest of the Pacific War; these reports were used by the most senior navy officers for strategic and tactical decisions.
Rochefort died in 1976. In 1986, he posthumously received the President’s National Defense Service Medal, the highest military award during peacetime, for his support to the Battle of Midway.
Featured image: Joe Rochefort — Japanese Interlude
Rochefort looked for opportunities to meet civilians and members of Japan’s military during his three years in Tokyo, 1929-32, studying the Japanese language. Rochefort (left) is pictured with a Japanese army officer and two members of the U.S. diplomatic community, all unidentified (Elliot Carlson). Photo credit: Janet Rochefort Elerding
12 May 2023 at 15:46
I had the honor of working for CAPT Rochefort’s son, also CAPT Joe, at NSGA Sugar Grove as Fire Chief. The command thought a lot of Capt Joe and his wife. A family of service.
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12 May 2023 at 18:57
As a Pearl Harbor research historian I have the utmost respect for Captain Rochefort. His work and that of the entire OP-20-G community certainly made a major contribution to the Allied victory in World War II.
In the eight government investigations into the Japanese raid on the Pacific Fleet of 7 December 1941, only two of the approximate 333 witnesses appeared in seven of those investigations. Joseph J. Rochefort and the Pacific Fleet’s intelligence officer, Captain Edwin T. Layton (later Rear Admiral), both testified in seven of those eight investigations. (Layton was a lieutenant commander when he testified before the Roberts Commission on 2 January 1942. On that same day, when Rochefort went before the Roberts Commission, he was a Commander as officer in charge of the Navy’s communications intelligence unit at Pearl Harbor.)
On Friday, 15 February 1946 during the Joint Congressional Committee’s Investigation of the Pearl Harbor Attack, both the general counsel, Seth W. Richardson, and the JCC’s chairman, Senator Alben W. Barkley, called “Admiral Rochefort” to take the witness stand. Upon being sworn in by Senator Barkley, Rochefort replied: “I was about to thank you, Senator, for promoting me. I am actually a captain.” Senator Barkley added: “Oh, yes. You are not adverse to a real promotion if it comes your way, I suppose.” Captain Rochefort then stated: “I would appreciate it, sir.” I suspect the reference by Seth Richardson and Senator Barkley was their way of saluting Captain Rochefort for his many accomplishments prior to and all throughout U.S. participation in the Second World War.
As a student of events leading up to United States entry into World War II, this writer is firmly of the belief that both Captain Joseph J. Rochefort and Captain Laurence F. Safford are long overdue for posthumous promotions to the rank of Rear Admiral, United States Navy.
Thank you, Mario, for today’s fine biographical sketch of Joseph J. Rochefort, United States Navy!
Happy Birthday, “Admiral Rochefort.”
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